Classifiers (i.e., classifiers) are used to automate recognition or classification of data. Classifiers can be simple or complex. A common application of a classifier is in digital image recognition, where an image is presented to a computer implementation of a classifier to identify some object in the image (e.g. a person's face, lines on a road, etc.). Classification has many applications including computer vision, medical imaging (X-ray, magnetic resonance imaging (“MRI”)), and face detection. Improvements in the efficiency and accuracy, flexibility for use in varied kinds of classification applications, and speed of generation of classifiers are desirable.